I have recently bought a Mk3 Golf 1.8CL complete with dented door but almost complete VW service history and 100K on the clock which seems to have a rattle thats either developed or i've just noticed. There also now seems to be more vibration on the accelerator pedal at motorway speeds now than there was. On startup from cold there's a brief rattly / knocky noise that's reminiscent of an old Triumph Vitesse i had with a shot bottom end. This settles down to a bit of a rattly clatter (which you can't hear in the car). It only seems to make the knocky noise on startup (but still rattles when warm), from cold which seems strange (if it was the bottom end), as i would have thought it would be more pronounced when warm (thin oil). I'm thinking of taking the sump off if it's accessable and seeing if there is a big end with more movement than the others. Am i barking up the wrong tree, if not is there any mileage in just changing the bearing shells rather than having the crank reground etc?
Any ideas?
|
|
Could be worn hydraulic tappets.Just a thought
|
|
thanks for the idea mech. Any quick ideas on how to differentiate it from the other (more terminal) problem?
|
|
Tappets start of really bad and slowly queiten down but not fully always tap depending how bad. Knocks will come from big ends but usually sounds like hammers floating around engine follows with poor oil pressure/small ends not as bad as big ends although some would dissagree. I would personaly go for tappets. I know some engines to have done over 200k without serious work done let me know
|
|
thanks mech. It sounds like one thing rather than many items in there if that makes sense. Doesn't sound like hammers either though. I tried the turn the engine off then ignition on straight away thing to see if there's a pause before the oil light comes on - no pause but there again the engines over £100K so would this be expected anyway. One further thing i just remembered, the oil seems blacker now than before a run to Bristol and back from London this weekend but is that just a result of zooming down the motorway and stirring up the detritus previously stuck inside? Worth a flush / oil change?
|
You would be better off waiting untill engine cold for oil check
but Doubt the oil is causing any problems. But it never hurts to change if not sure. I gather the new flushing oils are pretty good nowadays so it might be worth a go. The bristol run probably did stir it all up.not a bad thing. But that won\'t cure the tappets if that is the problem will be due to normal wear/tear I expect to be told if I`m wrong but I think that is the way to go. let me know how you do
|
|
i take your point. I suppose the next question is - is there a way of nailing it down as tappets? If it is tappets any point in worrying about it or just put it down to wear and tear and live with it?
|
An experienced ear can distinguish the two noises apart....
--
groups.msn.com/honestjohn/problems.msnw?Page=1 - Pictures say a thousand words.....
|
|
hmmmm. If it were mechanical lifters i'd be able to say - as hydraulic i wouldn't know. Do they make the same sort of noises?
|
|
DL is right. there is not a lot of difference between the two. sound much the same. camshaft noise which I did not mention is a little heavier and won`t go away due to cam lobe wear. Tappets can if not too serious be calmed down using an additive to the oil, but as I am not a lover of these would be inclined to get an expert opinion as it is not poss without hearing the tap to say what it is. best get someone that knows to have a listen
|
|
yup - how it sounds is the bottom line. I did however try the oil pressure turn on turn off trick with the engine cold. When the ignition is switched back on there's a second or 2 where the oil light flashes before staying on steadily rather than coming straight on as it does when warm. This makes me think the bottom end isn't too bad so that's encouraging.
|
|
If you suspect it's tappet rattle, you could try some Forté top end treatment.
Details here:-
www.honestjohn.co.uk/forum/post/index.htm?v=e&t=16...2
|
|
|
